Coagulation disorders such as thrombotic thrombocytopenic purpura (TTP, idiopathic thrombocytopenic purpura (ITP) and disseminated intravascular coagulation (DIC) may lead to noninflammatory purpura of the skin.

If a biopsy was taken (rare situation), one would find that the epidermis can be normal or necrotic. There would be thrombi in the dermal blood vessels with extravasated RBCs in the dermis. There should be sparse inflammation (Rapini).